From f18cb329c3113d269d6012c90bada8354455ca98 Mon Sep 17 00:00:00 2001
From: gconesab <gconesab@f7af4fe6-9843-0410-8265-dc069ae4e863>
Date: Mon, 12 Dec 2011 14:07:45 +0000
Subject: [PATCH]  Move radius calculation to method, add correction in case
 trigger and particle are close to 2pi phi boundary

---
 PWG4/PartCorrBase/AliIsolationCut.cxx | 29 ++++++++++++++++++++++++---
 PWG4/PartCorrBase/AliIsolationCut.h   |  3 ++-
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/PWG4/PartCorrBase/AliIsolationCut.cxx b/PWG4/PartCorrBase/AliIsolationCut.cxx
index 734d05d34e6..a46fb9c67c7 100755
--- a/PWG4/PartCorrBase/AliIsolationCut.cxx
+++ b/PWG4/PartCorrBase/AliIsolationCut.cxx
@@ -87,7 +87,7 @@ TString AliIsolationCut::GetICParametersList()
   return parList; 
 }
 
-//____________________________________________________________________________
+//____________________________________
 void AliIsolationCut::InitParameters()
 {
   //Initialize the parameters of the analysis.
@@ -164,8 +164,10 @@ void  AliIsolationCut::MakeIsolationCut(const TObjArray * plCTS,
         }
         return ;
       }
+      
       //Check if there is any particle inside cone with pt larger than  fPtThreshold
-      rad = TMath::Sqrt((eta-etaC)*(eta-etaC)+ (phi-phiC)*(phi-phiC));
+
+      rad = Radius(etaC, phiC, eta, phi);
       
       if(rad < fConeSize){
         if(bFillAOD) {
@@ -240,7 +242,9 @@ void  AliIsolationCut::MakeIsolationCut(const TObjArray * plCTS,
       }
       
       //Check if there is any particle inside cone with pt larger than  fPtThreshold
-      rad = TMath::Sqrt((eta-etaC)*(eta-etaC)+ (phi-phiC)*(phi-phiC));
+
+      rad = Radius(etaC, phiC, eta, phi);
+      
       if(rad < fConeSize){
         if(bFillAOD) {
           nclusterrefs++;
@@ -312,3 +316,22 @@ void AliIsolationCut::Print(const Option_t * opt) const
   printf("    \n") ;
   
 } 
+
+//___________________________________________________________________________
+Float_t AliIsolationCut::Radius(const Float_t etaC, const Float_t phiC, 
+                                const Float_t eta , const Float_t phi) const
+{
+  // Calculate the distance to trigger from any particle
+
+  Float_t dEta = etaC-eta;
+  Float_t dPhi = phiC-phi;
+  
+  if(TMath::Abs(dPhi) >= TMath::Pi()) 
+    dPhi = TMath::TwoPi()-TMath::Abs(dPhi);
+  
+  return TMath::Sqrt( dEta*dEta + dPhi*dPhi );
+  
+}
+
+
+
diff --git a/PWG4/PartCorrBase/AliIsolationCut.h b/PWG4/PartCorrBase/AliIsolationCut.h
index d7af49158fd..348dfa66a1b 100755
--- a/PWG4/PartCorrBase/AliIsolationCut.h
+++ b/PWG4/PartCorrBase/AliIsolationCut.h
@@ -51,6 +51,7 @@ class AliIsolationCut : public TObject {
   
   void       Print(const Option_t * opt) const ;
   
+  Float_t    Radius(const Float_t etaCandidate, const Float_t phiCandidate, const Float_t eta, const Float_t phi) const ; 
   
   // Parameter setters and getters
   
@@ -85,7 +86,7 @@ class AliIsolationCut : public TObject {
   AliIsolationCut(const AliIsolationCut & g) ;               // cpy ctor
   AliIsolationCut & operator = (const AliIsolationCut & g) ; // cpy assignment
   
-  ClassDef(AliIsolationCut,3)
+  ClassDef(AliIsolationCut,4)
 } ;
 
 
-- 
2.43.0